Rising oil costs and increasing concerns regarding environmental issues have placed greater emphasis on the pursuit of sustainable, renewable, alternative energy. This pursuit has fueled research for alternative energy in numerous different fields. Although many sources of alternative energy are available, some believe that the most viable sources of renewable alternative energy are wind power and solar power. Within solar power technology, different methods for harnessing the sun's energy are available. The more widely known type of solar power is solar thermal technology, which concentrates the sun's energy to heat a heat-transfer fluid. Solar thermal technology is employed in the solar power plants installed in the Mojave Desert in the western United States.
An alternate technology to solar thermal technology available for generating electricity from solar energy is Concentrated Photovoltaics (“CPV”). Unlike solar thermal technology, CPV directly converts sunlight into electricity. Although CPV technology has been widely known for years, it remained in the shadow of solar thermal technology until NASA incorporated CPV modules into its spacecraft.
CPV is regarded by some as the most promising utility-scale sustainable form of alternative renewable energy. Historically, CPV technology has yielded efficiency percentages in the mid to upper teens. However, with advances in technology, forecasters estimate that CPV has the potential of reaching and exceeding efficiencies of greater than 50%. One impediment to achieving higher efficiencies has been inadequate heat dissipation of CPV solar cells. The technology surrounding packaging of CPV chips has not kept pace with advances that have been achieved in CPV chip technology. These packages do not allow for sufficient cooling of CPV chips to achieve higher efficiencies.
Many CPV applications still use copper bonded ceramic substrate packages, known as direct copper bonding (“DBC”), for mounting CPV chips. DBC packages are made up of sheet copper bonded to ceramic plates, and is widely used in spacecraft applications. Although the design of these packages is well-established and stable, the packages are costly and inefficient. Furthermore, CPV technology typically utilizes a variety of optics systems to concentrate the incident solar energy. These optics systems typically incorporate large heavy lenses to focus incoming solar energy. These lenses are typically custom design units that are difficult to mount onto the existing and widely used DBC substrate packages.